Shuttle valve stabilization through pressure differential and shuttle valve with hollow poppet with weep hole

ABSTRACT

A shuttle valve has a valve body including a first valve seat defining a first fluid inlet, a second valve seat defining a second fluid inlet, and a center portion that is connected to the valve seats, the center portion defining a fluid outlet and a bore. A moveable member is moveable within the bore between a first position against the first valve seat and a second position against the second valve seat to control the flow of fluid from either of the first or second inlet to the outlet. The moveable member may be configured to have a unitary construction formed of a single component, by which a unitary shell defines a substantially hollow interior. The moveable member has a hollow interior and a weep hole for equalizing pressure between the hollow interior and exterior of the moveable member.

RELATED APPLICATIONS

The present application is a continuation of U.S. Patent Application No.15/075,853, filed on Mar. 21, 2016, and entitled “Shuttle ValveStabilization through Pressure Differential and Shuttle Valve withHollow Poppet with Weep Hole,” which claims the benefit of U.S.Provisional Application No. 62/137,275 filed Mar. 24, 2015, the entirecontents of all of which are herein incorporated by reference as iffully set forth in this description.

FIELD OF INVENTION

The present invention relates to shuttle valves, including shuttlevalves for hydraulic fluid systems, such as, for example, shuttle valveswhich may be employed in undersea drilling operations in offshoredrilling rig blowout preventers.

BACKGROUND OF THE INVENTION

As demand for crude oil and other fossils fuels has increased, the useof undersea drilling operations has expanded. Such operations, however,present an environmental risk in that catastrophic failure in drillingequipment could result in dangerous emission of oil leaking into theundersea environment. As a safety mechanism, undersea drillingoperations typically are equipped with blowout preventers. In the eventof a catastrophic failure of drilling equipment, the blowout preventersare triggered, which incorporate wedge-like blocking components thatdrive into the drill stream to cut off flow, thereby preventing leakageinto the environment.

The blowout preventers typically are powered using high pressureaccumulators, with the flow of the hydraulic fluid being controlled byvalve systems. Such valve systems typically may employ hydraulic shuttlevalves. A hydraulic shuttle valve generally includes a valve body havinga bore with two fluid inlets, one fluid inlet each on opposite ends ofthe bore. There also is a fluid outlet perpendicular to the bore andbetween the two fluid inlets. A moveable member rides in the bore of thevalve body, and shifts position between two stops or valve seats in thevalve body based on the pressures that occur at the two fluid inlets.The movable member will shift when there is a pressure differentialbetween the two fluid inlets to create a net force to shift the moveablemember against one of the valve seats, depending upon the direction ofthe pressure differential. The movable member will reach a physical stopon either side of the bore when the moveable member comes in contactwith one of the valve seats. Each valve seat may be integrated into anend cap, or constitute a separate component.

A shuttle valve generally is used as a junction between two separateupstream circuits and a single downstream function. In the case of ablowout preventer in an undersea drilling operation, for example, thetwo upstream circuits are separate control pods for sourcing hydraulicfluid that are required for redundancy in case of a failure of one ofthe circuits. Hydraulic fluid will flow in through one of the fluidinlets and then out through the common fluid outlet to actuate adownstream function, such as a large hydraulic cylinder or shear ram inorder to seal off the well head and prevent a blowout.

When the hydraulic cylinder retracts, a condition arises where hydraulicfluid will be flowing in the reverse direction, in through the fluidoutlet of the shuttle valve, and the reverse flow needs to evacuatethrough one of the two fluid inlets. During this condition, the shuttlevalve must remain biased towards one of the valve seats, for if themovable member were to shift to an intermediate position, the flow areawould be reduced resulting in a lower flow rate and ultimately a slowercylinder retraction time. In addition, an intermediate position can leadto an undesirable state of unstable “chatter”, in which the moveablemember rapidly moves back-and-forth between the two valve seats.Chattering also reduces the reverse flow rate for cylinder retraction,and increases wear on the shuttle valve due to the repeated impacts ofthe moveable member against the valve seats.

Shuttle valve stabilization, therefore, is important to maintain anefficient bias state of the moveable member towards one of the valveseats during the reverse flow. Conventional configurations for achievingsuch bias have significant drawbacks. Certain solutions attempt tomaintain the moveable member captive in one of the valves seats duringthe reverse flow. This typically requires that the reverse flow actuallybe forced through the moveable member itself, which minimizes flow area.Other conventional configurations have used o-rings or similarcomponents to provide friction to hold the moveable member toward thevalve seats. Such configurations, however, restrict the movement of themoveable member generally, thereby undesirably increasing the requisiteoperating flows and pressures. Such configurations further add acomponent to the valve system, which in some cases can fail resulting inundesired and potentially catastrophic system contamination.

Conventional shuttles valves have thus proven deficient in providing amaximum reverse flow rate for hydraulic cylinder retraction, whilepreventing the centering of the moveable member in an intermediate stateand unstable chattering.

SUMMARY OF THE INVENTION

The present invention provides an enhanced shuttle valve configurationfor biasing a moveable member against a valve seat during the reverseflow of a fluid, for example hydraulic fluid that powers a hydrauliccylinder. The configuration of the present invention stabilizes themovable member during reverse flow conditions, while also reducing thepressure differential across the shuttle valve without increasing theamount of flow required to shift the movable member of the shuttlevalve.

The configuration of the present invention provides an enhancedrelationship of the geometries of the movable member and valve body asthe moveable member shifts within the bore. One or more pressuredifferential grooves are machined into an outermost diameter of themovable member. The grooves are machined less than the entire length ofthe outer diameter so as not to create a flow path across the shuttlevalve. Additionally, one or a plurality of annuluses or cavities aremachined into the bore of the body directly in plane with a center axisof the fluid outlet of the shuttle valve and symmetrical to either side.When a cylinder retracts creating a reverse flow condition, hydraulicfluid surrounds the movable member by traveling through the cavities,which in turn feeds the hydraulic fluid into the pressure differentialgrooves. The velocity of the hydraulic fluid that enters a pressuredifferential groove is dependent on the specific location of themoveable member relative to the downstream fluid inlets.

During a reverse flow scenario, with the shuttle valve moveable memberalready initially biased towards one fluid inlet (the closed fluidinlet), the accompanying end of the pressure differential grooves has nopath for the fluid to escape and therefore creates a stagnant flow(higher pressure) area. The opposite end of the pressure differentialgrooves has a flow path from the fluid outlet downstream to the openfluid inlet, creating a high velocity flow (low pressure) area. Thisdifferential in pressure will create a net force towards the biasedfluid inlet, which in turn stabilizes the moveable member and maximizesthe flow area for the reverse flow. The result is an enhancedconfiguration having a larger reverse flow area and smaller pressuredrop as compared to conventional configurations, while maintaining themovable member stable during the reverse flow conditions.

An aspect of the invention is a shuttle valve. Another aspect of theinvention is a moveable member for use in the shuttle valve.

In exemplary embodiments, the shuttle valve may include a valve bodyhaving a first valve seat defining a first fluid inlet, a second valveseat defining a second fluid inlet, and a center portion that isconnected to the first valve seat and the second vale seat, the centerportion defining a fluid outlet and a bore. A moveable member ismoveable within the bore between a first position against the firstvalve seat and a second position against the second valve seat. When themoveable member is in the first position, the second fluid inlet is influid communication with the fluid outlet, and when the moveable memberis in the second position, the first fluid inlet is in fluidcommunication with the fluid outlet. The moveable member has at leastone groove formed in an outer diameter portion of the moveable member,and during a reverse flow condition in which fluid flows from the fluidoutlet, fluid flows into the at least one groove to bias the moveablemember against either the first valve seat or the second valve seat.

The shuttle valve further may include a first cavity and a second cavityin fluid communication with the fluid outlet. When the moveable memberis in the first position, the second fluid inlet is in fluidcommunication with the second cavity to permit a reverse flow betweenthe second cavity and the second fluid inlet, thereby creating a highvelocity flow area at one end of the at least one groove adjacent thesecond fluid inlet. Furthermore, when the moveable member is in thefirst position, the moveable member blocks a reverse flow between thefirst cavity and the first fluid inlet, thereby creating a stagnant flowarea in an end of the at least one groove adjacent the first fluidinlet. A pressure differential between the high velocity flow area andthe stagnant flow area biases the moveable member against the firstvalve seat.

Similarly, when the moveable member is in the second position, the firstfluid inlet is in fluid communication with the first cavity to permit areverse flow between the first cavity and the first fluid inlet, therebycreating a high velocity flow area at the end of the at least one grooveadjacent the first fluid inlet. Furthermore, when the moveable member isin the second position, the moveable member blocks a reverse flowbetween the second cavity and the second fluid inlet, thereby creating astagnant flow area in the end of the at least one groove adjacent thesecond fluid inlet. A pressure differential between the high velocityflow area and the stagnant flow area biases the moveable member againstthe second valve seat.

In exemplary embodiments, the moveable member may include a plurality ofgrooves spaced equidistantly about a circumference of the moveablemember. The grooves may extend less than an entire length of the outerdiameter of the moveable member so as not to form a complete flow pathover the moveable member. The moveable member may have a substantiallyhollow interior for reduction of weight and reduction in impacting shockloads induced by the moveable member, and a weep hole for equalizingpressure between the hollow interior and an exterior of the moveablemember.

These and further features of the present invention will be apparentwith reference to the following description and attached drawings. Inthe description and drawings, particular embodiments of the inventionhave been disclosed in detail as being indicative of some of the ways inwhich the principles of the invention may be employed, but it isunderstood that the invention is not limited correspondingly in scope.Rather, the invention includes all changes, modifications andequivalents coming within the spirit and terms of the claims appendedhereto. Features that are described and/or illustrated with respect toone embodiment may be used in the same way or in a similar way in one ormore other embodiments and/or in combination with or instead of thefeatures of the other embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing depicting a side cross-sectional view of anexemplary shuttle valve in accordance with embodiments of the presentinvention.

FIG. 2 is a drawing depicting a perspective view of an exemplarymoveable member for use in the shuttle valve of FIG. 1.

FIG. 3 is a drawing depicting an exploded perspective view of themoveable member of FIG. 2.

FIG. 4 is a drawing depicting a second exploded perspective view of themoveable member of FIG. 2, from the opposite viewpoint of FIG. 3.

FIG. 5 is a drawing depicting a side cross-sectional view of theexemplary moveable member for use in the shuttle valve of FIG. 1.

FIG. 6 is a drawing depicting a side cross-sectional view of anotherexemplary moveable member, having a unitary construction, for use in ashuttle valve in accordance with embodiments of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention will now be described withreference to the drawings, wherein like reference numerals are used torefer to like elements throughout. It will be understood that thefigures are not necessarily to scale. In addition, although the presentinvention at times is described with respect to an exemplary usage ofcontrolling hydraulic fluid flow to and from a hydraulic cylinder, andfor an undersea drilling blowout preventer in particular, it will beappreciated that the present invention is not limited to any specificusage. Rather, the present invention may be utilized in any suitableapplication in which shuttle valves are employed.

FIG. 1 is a drawing depicting a side cross-sectional view of anexemplary shuttle valve 10 in accordance with embodiments of the presentinvention. The shuttle valve 10 includes a valve body 12, and a moveablemember 14 that is moveable within the valve body. More specifically, thevalve body 12 includes a center portion 16 that has a bore 18 in whichthe moveable member moves. The moveable member and the components of thevalve body may be made of various metals, rigid plastics, and othersuitable materials as are known in art for use in shuttle valves.Components of the valve body and moveable member may be made of the samematerials, or be made of different materials. On opposite sides of thecenter portion 16, the valve body further includes a first valve seat 20and a second valve seat 22. The first valve seat 20 defines a firstfluid inlet 24, and the second valve seat 22 defines a second fluidinlet 26. The shuttle valve structure is secured and supported byproviding a first end cap 28 connected to the first valve seat 20, and asecond end cap 30 connected to the second valve seat 22. The centerportion 16 further defines a fluid outlet 32 that is perpendicular tothe bore 18. The fluid outlet 32 is in fluid communication with eitherof the first fluid inlet 24 or second fluid inlet 26, depending upon theposition of the moveable member 14.

The shuttle valve 10 may provide for control of a fluid flow through thevalve, such as for example a control of hydraulic fluid. As isconventional, the moveable member 14 rides in the bore 18 of the valvebody 12, and shifts position between two stops constituting the valveseats 20 and 22 in the valve body based on the pressures that occur atthe two fluid inlets. The movable member will shift when there is apressure differential between the two fluid inlets 24 and 26 to create anet force to shift the moveable member against one of the valve seats,depending upon the direction of the pressure differential. The movablemember will reach a physical stop on either side of the bore 18 when themoveable member comes into contact with or against one of the valveseats 20 and 22.

The positioning of the moveable member 14 within the bore 18 controlsthe fluid flow through the shuttle valve. For example, when the pressuredifferential forces the moveable member 14 against the first valve seat20, the second fluid inlet 26 and the fluid outlet 32 are in fluidcommunication to permit a forward fluid flow through the second fluidinlet 26 and then through the fluid outlet 32. Similarly, when thepressure differential forces the moveable member 14 against the secondvalve seat 22, the first fluid inlet 24 and the fluid outlet 32 are influid communication to permit a forward fluid flow through the firstfluid inlet 24 and then through the fluid outlet 32. As referencedabove, the forward fluid flow from either fluid inlet and through thefluid outlet may provide fluid for a downstream function, such asproviding a flow of hydraulic fluid to power a hydraulic cylinder.

As referenced above, the present invention provides an enhanced shuttlevalve configuration for biasing the moveable member against one of thevalve seats during a reverse flow of the fluid, such as, for example,the reverse flow of hydraulic fluid during retraction of the referencedhydraulic cylinder. The biasing of the moveable member during reverseflow may be described with reference to FIG. 1 in combination with FIG.2. FIG. 2 is a drawing depicting a perspective view of an exemplarymoveable member 14 for use in the shuttle valve of FIG. 1.

As seen in FIG. 1, the fluid outlet 32 in the center portion 16 mayinclude one or more annuluses or cavities that define distinct flowpaths. In the example of FIG. 1, the fluid outlet may include a firstcavity 34 and a second cavity 36. The cavities may be machined into thevalve body and be located directly in plane with a center axis of thefluid outlet 32 of the shuttle valve and symmetrical to either side asseen in FIG. 1. The cavities 34 and 36 may be configured with a depthand width as warranted for accommodating the outer diameter of themoveable member and other dimensions of the shuttle valve components. Ina forward flow state, the first cavity 34 communicates fluid through theshuttle valve that flows from the first fluid inlet 24 to the fluidoutlet 32, and the second cavity 36 communicates fluid through theshuttle valve that flows from the second fluid inlet 36 to the fluidoutlet 32. The two cavities provide distinct and isolated fluid pathwaysthat are not in fluid communication with each other in the area of themoveable member 14. In the state of the shuttle valve as depicted inFIG. 1, the moveable member 14 is against the second valve seat 22. Insuch state, fluid flow (forward or reverse) can occur between the firstfluid inlet 24 and the first cavity 34. The moveable member, however,blocks any fluid flow between the second fluid inlet 26 and the secondcavity 36. Under different circumstances of operation, the pressuredifferential between the fluid inlets alternatively may force themoveable member 14 against the first valve seat 20. It will beappreciated that in such state, fluid flow (forward or reverse) canoccur between the second fluid inlet 26 and the second cavity 36. Themoveable member, however, blocks any fluid flow between the first fluidinlet 24 and the first cavity 34.

As best depicted in FIG. 2 (and depicted partially in FIG. 1), themoveable member 14 may include at least one or a plurality of pressuredifferential grooves 40 formed in an outer diameter portion of themoveable member. The grooves 40 are machined to extend less than theentire length of the outer diameter so as not to create a flow pathacross the shuttle valve. The depths of the grooves may be configured aswarranted for accommodating the outer diameter and/or other dimensionsof the moveable member. In the example of FIG. 2, there are six grooves40, and the grooves are spaced equidistantly about a circumference ofthe moveable member. The precise number of grooves may vary dependingupon the dimensions of the moveable member and overall shuttle valve.For example, four grooves may be employed for small configurations,eight grooves may be employed for larger configurations, and so on. Ingeneral, the higher the number of grooves, the larger the pressuredifferential created across the moveable member.

Looking at the state of FIG. 1, as referenced above in this state themoveable member 14 is forced against the second valve seat 22, suchstate initially being created due to the pressure differential of theforward fluid flow. When a cylinder retracts creating a reverse flowcondition, fluid (e.g., hydraulic fluid) surrounds the movable member 14by traveling through the cavities 34 and 36, which in turn feeds thefluid into the pressure differential grooves 40. The velocity of thehydraulic fluid that flows through a pressure differential groove 40will be dependent upon the specific location of the moveable memberbetween a first position and a second position relative to either of thereverse flow downstream fluid inlets 24 or 26 and against the valveseats 20 or 22.

During the reverse flow scenario as depicted in FIG. 1, with themoveable member already initially forced against the second valve seat22 (closing the second fluid inlet 26 in this state), the correspondingend of the pressure differential grooves 40 have no path for the fluidto escape between the second cavity 36 and the second fluid inlet 26.This creates a stagnant flow (higher pressure) area at an end of thegrooves adjacent to the second fluid inlet 26. The opposite ends of thepressure differential grooves 40 have an open flow path from the firstcavity 34 of the fluid outlet downstream to the open first fluid inlet24, creating a high velocity flow (low pressure) area at an end of thegroove adjacent the first fluid inlet 24. A pressure differential isthereby created between the high velocity flow area and the stagnantflow area, and this pressure differential will create a net force thatbiases the moveable member against the second valve seat 22. This biasstabilizes the moveable member 14 and maximizes the flow area for thereverse flow through the first cavity 34 and out of the first fluidinlet 24.

It will be appreciated that opposite bias control of the moveable member14 occurs when the moveable member is forced against the first valveseat 20 due to the pressure differential initially created by theforward fluid flow. In such state, when the cylinder retracts creatingthe reverse flow condition, the ends of the pressure differentialgrooves 40 have no path for the fluid to escape between the first cavity34 and the first fluid inlet 24. This creates a stagnant flow (higherpressure) area at the end of the grooves adjacent the first fluid inlet24. The opposite end of the pressure differential grooves 40 now have anopen flow path from the second cavity 36 of the fluid outlet downstreamto the now open second fluid inlet 26, creating a high velocity flow(low pressure) area at the end of the grooves adjacent the second fluidinlet 26. A pressure differential is thereby created between the highvelocity flow area and the stagnant flow area, and this pressuredifferential will create a net force that biases the moveable memberagainst the first valve seat 20. This bias similarly stabilizes themoveable member 14 and maximizes the flow area for the reverse flowthrough the second cavity 36 and out of the second fluid inlet 26.

The result is an enhanced configuration having a larger reverse flowarea and smaller pressure drop as compared to conventionalconfigurations, while maintaining the movable member stable during thereverse flow conditions. The groove/cavity relationship renders theshuttle valve capable operating with a lower pressure drop through thevalve without increasing the flow required to shift the movable member.It is advantageous to have the lowest pressure drop possible through thevalve because the pressure drop directly correlates to the amount offlow that can go through the valve in a given amount of time. A lowpressure drop through the valve equates to more flow through the valveand faster cycle times for the downstream cylinders and actuators.Particularly for undersea drilling operations, there may be, forexample, emergency instances for a blowout preventer when the cylinderswill have to be actuated by a remote operated vehicle (ROV). An ROV doesnot have the same flow capabilities as the hydraulic fluid control podsof the drilling equipment, which makes it important for the shuttlevalve to be able to actuate under low flow conditions. The groove/cavityconfiguration is advantageous in creating a larger flow path, loweringthe pressure drop only to the open fluid inlet. The full outsidediameter of the movable member is still present at the closed off fluidinlet with only the bore/movable member leakage increasing the requiredflow to shift. None of these performance advantages are as effectivelyachieved by any of the conventional configurations.

The moveable member 14 has additional features that improve theperformance of the shuttle valve. Such features are best seen in FIGS.3-5 showing various views of the moveable member 14. In particular, FIG.3 is a drawing depicting an exploded perspective view of the moveablemember of FIG. 2. FIG. 4 is a drawing depicting a second explodedperspective view of the moveable member of FIG. 2, from the oppositeviewpoint of FIG. 3. FIG. 5 is a drawing depicting a sidecross-sectional view of the exemplary moveable member for use in theshuttle valve of FIG. 1. Accordingly, like components are identifiedwith common reference numerals in FIGS. 2-5.

As seen particularly in FIGS. 3-5, the moveable member 14 may include afirst component 50 and a second component 52. The first component 50 maybe a male component and the second component 52 may be a femalecomponent, and the male component is inserted into the female component.The first component 50 may include a first head portion 54 and a baseportion 56. The first head portion 54 may interact with or contactagainst the first valve seat 20 of the valve body in the mannerdescribed above. The second component 52 may include a barrel portion 58and a second head portion 60. The second head portion may interact withor contact against the second valve seat 22 of the valve body in themanner described above. The barrel portion 58 may include the pressuredifferential grooves 40 described above formed in an outer diameter ofthe barrel portion. The barrel portion 58 further may include additionalnotches 62. The notches 62 may enhance fluid flow from the valve fluidinlets to the valve fluid outlet in the forward flow state.

As seen in FIG. 3, the barrel portion 58 of the second component 52generally is hollowed out to form a first hollow bore 64. The firsthollow bore 64 may extend into the second head portion 60. Similarly, asseen in FIG. 4, the base portion 56 of the first component 50 generallyis hollowed out to form a second hollow bore 66. The second hollow bore66 may extend into the first head portion 54.

The cross-sectional view of FIG. 5 (see also FIG. 1) shows the manner bywhich the components of the moveable member 14 are fitted and joinedtogether. Generally, the base portion 56 of the first or male component50 is inserted into the barrel portion 58 of the second or femalecomponent 52. The two components may be secured together by a tightpress-fit relationship, brazing, welding, use of adhesives, or anysuitable means. As seen in FIG. 5, an outer diameter of the base portion56 of the first component 50 is located against an inner diameter of thebarrel portion 58 of the second component 52, with the first headportion 54 extending outwardly from the barrel portion 58. In addition,the base portion 56 extends only partially into first hollow bore 64 ofthe barrel portion 58. Furthermore, hollow bores 64 and 66 generallyhave a thickness or diameter substantially greater than thicknesses ofthe material of the first and second components of the moveable member.The result is that when the two components of the moveable member 14 arejoined together, the moveable member 14 has a substantially hollowinterior. Specifically, when the base portion of the male component isinserted into the barrel portion of the female component, the first andsecond hollow bores 64 and 66 join to form the hollow interior of themoveable member.

Configuring the moveable member with a substantially hollow interior hasperformance advantages. The moveable member needs to be able to movewithin the valve body with significant speed, and sometimes back andforth in rapid succession. The hollow nature of the moveable memberreduces its mass for reduction in impacting shock loads induced by themoveable member stopping in the seat, as compared to a non-hollowconfiguration. This provides for easier movement for enhanced control ofthe fluid flow. In this regard, as referenced above many conventionalshuttle valves are configured for fluid flow through the moveable memberitself. In such configurations, a substantially hollow moveable memberis not usable because the configuration of the flow paths through themoveable member would not be proper. The shuttle valve stabilization ofthe present invention, as described above, is achieved without directingfluid flow through the moveable member itself. This permits the moveablemember to be made hollow so as to achieve the reduced mass advantages incontrast to conventional configurations.

As also depicted in FIGS. 1-5, the moveable member 14 may include a weephole 70 that performs a pressure equalization function for equalizingpressure between the hollow interior and an exterior of the moveablemember. Due to the multiple component nature of the moveable member 14,some leakage of fluid potentially can occur into the hollow interior. Atsub-sea depths during operation, with such leakage the pressure isessentially equal as between the hollow interior of the moveable memberand the external environment. The sub-sea depths of operation, however,are at a pressure many magnitudes greater than that of atmosphericpressure at the surface.

The pressure at depth can create a danger for maintenance performed atsurface pressure. Sometimes for maintenance or replacement, the shuttlevalve may be removed and taken to the surface. As the moveable member isbrought toward the surface, the external environmental pressuredecreases toward surface atmospheric pressure, whereas the enclosedhollow interior of the moveable member may tend to stay at thesubstantially greater depth pressure. If this pressure differential werenot equalized, the enormous pressure retained in the hollow interior ofthe moveable member could present a danger of explosion. To eliminatesuch danger, the weep hole 70 provides a pathway for equalization ofpressure between the hollow interior of the moveable member and theexternal environment at the exterior of the moveable member.

As described above, in the embodiments of FIGS. 3-5, the moveable membermay be formed of separate components, such as a first male component anda second female component, with the male component being inserted intothe female component. Forming the moveable member as two separatecomponents, however, can have disadvantages in manufacturing. Suchcomponents typically may be joined together by conventional processingmethods, whether permanent or semi-permanent, such as welding, brazing,press fit, shrink fit, threading, or like processes. Such additionalprocessing adds to the complexity and cost of manufacturing. Machiningcapabilities also limit the ability to optimize the internal cavities ofthe two mating components for the greatest weight reduction and impactabsorption.

As an alternative configuration, FIG. 6 is a drawing depicting a sidecross-sectional view of another exemplary moveable member 80. Incontrast to the previous embodiment, the moveable member 80 isconfigured having a unitary construction formed of a single component,rather than being formed of separate components that subsequently arejoined together. In exemplary embodiments, the unitary construction isachieved using a three-dimensional (3D) printing process as are becomingmore available and enhanced.

By forming the moveable member 80 using a 3D printing process to have aunitary construction, the manufacturing is optimized as to all features.In particular, the internal cavity of the moveable member can be formedto have the greatest weight reduction, performance, and impactabsorption, while reducing cost insofar as limits of conventionalmachining processes are avoided. Engineering design optimization andweight reduction, implemented with 3D printing, leads to a cheapermoveable member, since printing processes generally are priced by weightand time. Applying 3D printing to the moveable member or likecomponents, where weight reduction has an enormous effect on impactwithin the shuttle valve, in turn enhances life, longevity, and overallreliability of the valve and the valve components. The 3D printingmanufacturing process and design techniques can be applied to a widevariety of applications, and the unitary construction thus has expandedthe use of the principles of the present invention into fields and usesthat previously have been unavailable.

The resultant configuration of the moveable member 80 manufactured by 3Dprinting otherwise may be comparable to that of the moveable member 14as shown in FIG. 2. Looking more at the specific embodiment of FIG. 6,the moveable member 80 may include a unitary shell 82 that defines ashaped cavity 84. The cavity 84 may be shaped through 3D printing toconform to the grooves and notches formed into the moveable member thatare detailed above. In this manner, the expanse of the hollow portion ofthe moveable member is maximized to provide the desired weightreduction, while maintaining effective performance. More specifically,the shell 82 of the moveable member may include a first head portion 86,a second head portion 88, and a barrel portion 90 between the first andsecond head portions, which define a substantially hollow interiorconstituting the shaped cavity 84. In this embodiment, the moveablemember is configured to have a unitary construction formed of a singlecomponent, by which the unitary shell comprises the first head portion,the second head portion, and the barrel portion.

The moveable member 80 further may include a weep hole 92 that extendsfrom an outer surface of the moveable member 80, through the shell 82 tothe cavity 84. As described above, the weep hole 92 performs a pressureequalization function for equalizing pressure between the hollowinterior and an exterior of the moveable member.

An aspect of the invention, therefore, is a shuttle valve. In exemplaryembodiments, the shuttle valve includes a valve body comprising a firstvalve seat defining a first fluid inlet, a second valve seat defining asecond fluid inlet, and a center portion that is connected to the firstvalve seat and the second vale seat, the center portion defining a fluidoutlet and a bore. A moveable member is moveable within the bore betweena first position against the first valve seat and a second positionagainst the second valve seat, wherein when the moveable member is inthe first position, the second fluid inlet is in fluid communicationwith the fluid outlet and when the moveable member is in the secondposition, the first fluid inlet is in fluid communication with the fluidoutlet. The moveable member has at least one groove formed in an outerdiameter portion of the moveable member, and during a reverse flowcondition in which fluid flows from the fluid outlet, fluid flows intothe at least one groove to bias the moveable member against either thefirst valve seat or the second valve seat.

In an exemplary embodiment of the shuttle valve, the shuttle valvefurther includes a first cavity and a second cavity in fluidcommunication with the fluid outlet. When the moveable member is in thefirst position, the second fluid inlet is in fluid communication withthe second cavity to permit a reverse flow between the second cavity andthe second fluid inlet, thereby creating a high velocity flow area at anend of the at least one groove adjacent the second fluid inlet. Furtherwhen the moveable member is in the first position, the moveable memberblocks a reverse flow between the first cavity and the first fluidinlet, thereby creating a stagnant flow area at an end of the at leastone groove adjacent the first fluid inlet. A pressure differentialbetween the high velocity flow area and the stagnant flow area biasesthe moveable member against the first valve seat.

In an exemplary embodiment of the shuttle valve, when the moveablemember is in the second position, the first fluid inlet is in fluidcommunication with the first cavity to permit a reverse flow between thefirst cavity and the first fluid inlet, thereby creating a high velocityflow area at the end of the at least one groove adjacent the first fluidinlet. Further when the moveable member is in the second position, themoveable member blocks a reverse flow between the second cavity and thesecond fluid inlet, thereby creating a stagnant flow area at the end ofthe at least one groove adjacent the second fluid inlet. A pressuredifferential between the high velocity flow area and the stagnant flowarea biases the moveable member against the second valve seat.

In an exemplary embodiment of the shuttle valve, the first and secondcavities are located in plane with a center axis of the fluid outlet andsymmetrical to either side of the fluid outlet.

In an exemplary embodiment of the shuttle valve, the fluid outlet isperpendicular to the bore.

In an exemplary embodiment of the shuttle valve, the at least one grooveextends less than an entire length of the outer diameter of the moveablemember.

In an exemplary embodiment of the shuttle valve, the at least one groovecomprises a plurality of grooves spaced equidistantly about acircumference of the moveable member.

In an exemplary embodiment of the shuttle valve, the number of groovesis six.

In an exemplary embodiment of the shuttle valve, the moveable member hasa substantially hollow interior.

In an exemplary embodiment of the shuttle valve, the moveable member hasa weep hole for equalizing pressure between the hollow interior and anexterior of the moveable member.

Another aspect of the invention is a moveable member for use in ashuttle valve. In exemplary embodiments, the moveable member includes afirst head portion, a second head portion, and a barrel portion betweenthe first and second head portions. The moveable member has at least onegroove formed in an outer diameter of the barrel portion of the moveablemember.

In an exemplary embodiment of the moveable member, the at least onegroove extends less than an entire length of the outer diameter of thebarrel portion of the moveable member.

In an exemplary embodiment of the moveable member, the at least onegroove comprises a plurality of grooves spaced equidistantly about acircumference of the barrel portion of the moveable member.

In an exemplary embodiment of the moveable member, the number of groovesis six.

In an exemplary embodiment of the moveable member, the moveable memberhas a substantially hollow interior.

In an exemplary embodiment of the moveable member, the moveable memberhas a weep hole for equalizing pressure between the hollow interior andan exterior of the moveable member.

In an exemplary embodiment of the moveable member, the moveable memberincludes a first component and a second component that are fittedtogether, wherein the moveable member has a substantially hollowinterior.

In an exemplary embodiment of the moveable member, the first componentis a male component and the second component is a female component, andthe male component is inserted into the female component.

In an exemplary embodiment of the moveable member, the male componentcomprises a first head portion and a base portion, the base portiondefining a first hollow bore, and the female component comprises asecond head portion and a barrel portion, the barrel portion defining asecond hollow bore. The base portion of the male component is insertedinto the barrel portion of the female component, the first and secondhollow bores joining to form the hollow interior of the moveable member.

In an exemplary embodiment of the moveable member, the first hollow boreextends into the first head portion, and the second hollow bore extendsinto the second head portion.

In an exemplary embodiment of the moveable member, the moveable memberis configured to have a unitary construction formed of a singlecomponent.

In an exemplary embodiment of the moveable member, the moveable memberis configured to have a unitary construction formed of a singlecomponent comprising the first head portion, the second head portion,and the barrel portion.

In an exemplary embodiment of the moveable member, the moveable memberhas a weep hole for equalizing pressure between the hollow interior andan exterior of the moveable member.

In an exemplary embodiment of the moveable member, the moveable memberhas at least one groove formed in an outer diameter of the secondcomponent of the moveable member.

In an exemplary embodiment of the moveable member, the at least onegroove extends less than an entire length of the outer diameter of thesecond component of the moveable member.

In an exemplary embodiment of the moveable member, the at least onegroove comprises a plurality of grooves spaced equidistantly about acircumference of the second component of the moveable member.

In an exemplary embodiment of the moveable member, the number of groovesis six.

Although the invention has been shown and described with respect to acertain embodiment or embodiments, it is obvious that equivalentalterations and modifications will occur to others skilled in the artupon the reading and understanding of this specification and the annexeddrawings. In particular regard to the various functions performed by theabove described elements (components, assemblies, devices, compositions,etc.), the terms (including a reference to a “means”) used to describesuch elements are intended to correspond, unless otherwise indicated, toany element which performs the specified function of the describedelement (i.e., that is functionally equivalent), even though notstructurally equivalent to the disclosed structure which performs thefunction in the herein illustrated exemplary embodiment or embodimentsof the invention. In addition, while a particular feature of theinvention may have been described above with respect to only one or moreof several illustrated embodiments, such feature may be combined withone or more other features of the other embodiments, as may be desiredand advantageous for any given or particular application.

What is claimed is:
 1. A shuttle valve comprising: a valve bodycomprising: a first valve seat defining a first fluid inlet, a secondvalve seat defining a second fluid inlet, and a center portion that isconnected to the first valve seat and the second valve seat, wherein thecenter portion defines a fluid outlet and a bore; and a moveable memberthat is moveable within the bore between a first position against thefirst valve seat and a second position against the second valve seat,wherein when the moveable member is in the first position, the secondfluid inlet is in fluid communication with the fluid outlet and when themoveable member is in the second position, the first fluid inlet is influid communication with the fluid outlet, and wherein the moveablemember comprises: a shell that defines a hollow interior, wherein theshell is configured to have a unitary construction formed of a singlecomponent that comprises a first head portion, a second head portion,and a barrel portion disposed between the first head portion and thesecond head portion, wherein the shell comprises at least onelongitudinal groove formed in an exterior surface of the shell.
 2. Theshuttle valve of claim 1, wherein the at least one longitudinal grooveis formed in an exterior surface of the barrel portion of the shell. 3.The shuttle valve of claim 2, wherein the at least one longitudinalgroove extends less than an entire length of the barrel portion.
 4. Theshuttle valve of claim 1, wherein the at least one longitudinal groovecomprises a plurality of longitudinal grooves spaced equidistantly abouta circumference of the barrel portion.
 5. The shuttle valve of claim 4,wherein the plurality of longitudinal grooves comprises six longitudinalgrooves.
 6. The shuttle valve of claim 1, wherein the barrel portion hasa first outer diameter, and wherein the first head portion and thesecond head portion have a second outer diameter that is smaller thanthe first outer diameter, and wherein the at least one longitudinalgroove is formed in an exterior surface of the barrel portion having thefirst outer diameter.
 7. The shuttle valve of claim 1, wherein themoveable member has a weep hole for equalizing pressure between thehollow interior and an exterior of the moveable member.
 8. The shuttlevalve of claim 7, wherein the weep hole is disposed in the barrelportion of the shell.
 9. The shuttle valve of claim 8, wherein the weephole is disposed in one of the at least one longitudinal groove.
 10. Theshuttle valve of claim 1, wherein the fluid outlet is perpendicular tothe bore.